Numerical counter



March 6, 1951 M. L. NELSON 2,544,610

NUMERICAL COUNTER Filed Aug. 14, 1947 6 Sheets-Sheet l lu's March 6, 1951 M. L, NELSON 2,544,610

NUMERICAL COUNTER Filed Aug. 14, 1947 6 Sheets-Sheet 2 Ma '12 L fifelspn,

5 Q. J W I /u's Rigg- March 6, 1951 NELSON 2,544,610

NUMERICAL COUNTER Filed Aug. 14, 1947 6 Sheets-Sheet 3 March 6, 1951 M. L. NELSON 2,544,610

NUMERICAL COUNTER Filed Aug. 14, 1947 6 Sheets-Sheet 4 March 6, 1951 M. L. NELSON NUMERICAL COUNTER 6 Sheets-Sheet 5 Filed Aug. 14, 1947 Adar Zl/VkZSUn, W

March 6, 1951 M. L. NELSON 2,544,610

NUMERICAL COUNTER Filed Aug. 14, 1947 3 6 Sheets-Sheet 6 I 1 l a Mari L. jl/Elsan,

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Patented Mar. 6, 1951 UNITED STATES PATENT OFFICE NUMERICAL ooUN'rER Martin L. Nelson, Park RidgejIlL, assignor to Production Instrument Company, Chicago, 111., a corporation of Illinois I e Application Augustl4, 1947, Serial No.1768,631

[This invention is concerned with a numerical counter having a plurality of number wheels and impulse-controlled electromagnetic means for advancing such number wheels to display successively numerals of progressively higher nu-' merical order.

An object of the invention is to provide a numerical counter'of the type noted above, comprising a drive shaft which may be continuously rotated, drive means in frictional driving engagement with said shaft, one for each number wheel, electromagnetically operable means for inter mittently coupling with said drive shaft the drive means associated with the number wheel of lowest numerical order for the purpose of successively operatively' advancing such number wheel by angular amounts corresponding to the spacing between'its numerals, and interlocking control meanso'perated by each number wheel upon completing a 'full revolution for operatively 9 Claims; (01. 235-92) Like parts are numbered alike throughout the drawings.

ing an understanding of the invention.

The counter illustrated in the drawings comprises a mounting member forming a side wall and I3.

coupling with said drive'shaft the drive wheel associated with the number wheel of next higher numerical order to cause rotation of such number wheel by a corresponding angular amount.

Another object is to provide a numerical counter, as noted in the preceding paragraph, wherein the drive shaft may be rotated in reverse direction for the purpose of rotating to 0 all number wheels which had been advanced incident to the forward rotation thereof, and having control means for stopping the reverse rotation of each number wheel upon reaching its 0 position. I The objects intimated above and other objects and features .will appear'from the detailed de-- scription of an embodiment'whlch is rendered below with reference to the accompanying-draw ings. In these drawings," Fig. 1 shows diagrammatically the'iront elevational view of an embodiment of a numerical counter in which the improvements. forming the subject-matter of the invention have been in corporated;

. Fig; 2 indicates a top elevational view of the structure; j V

Fig. 3 is a front view analogous to Fig. 1, with the number wheels removed and with some parts i'nsection and broken away to show details; 1 Figs. 4-7, inclusive illustrative the operation of the units number wheel; and

Figs. 8 and 9 are diagrams to assist in explaining the transfer mechanism for causing the operation of number-wheels of next "higher numerical order incident" to the-completion of a iull revolution of a number wheel of lower num rical or r H and an angular extension l2, and a mounting member forming a side wall l3 and an angular extension I l. Two rodlike members l5-l6 are providedfor interconnecting the side walls H which is indicated in Figs. 1 and 2 in dotted lines." In this .cover are formed sight openingsfor framing the numerals for display, as indicated in Fig. l in dot-dash lines, the number wheels being assumed to be in 0 position.

A suitable reversible motorlfl is mounted on a side wall [3 by means of posts, as shown. The motor shaft carries a pinion 2| which meshes with the gear wheel 22, and rotatable with the latter is a pinion 23 which meshes with the gear wheel 24, the latter gear wheel being keyed to the drive shaft 25. This drive shaft therefore may be selectively rotated in either direction of rotation. I

Keyed to the drive shaft 25 is a bushinglike member 26 provided with a flange 21 and a bushinglike member 28 carrying a flange 29. floating similarly flanged bushing 30 coacts with the bushing'26 and its flange 21, and a flanged floating bushing 3| coacts with the bushing 28 and its flange 29. Between the flanges of the bushings 26'and 3B is disposed a drive gear wheel 32 which is the-units drive Wheel of the structure, and between the flanges of the bushings 28- and 3l-is similarly disposed the drive gear wheel Which is the tens drive wheel. These drive wheels are made of suitable material and are freely rotatable on the shaft 25, being frictionally coupled therewith by the flanges carried on the fioating bushing members 30--3l which are resiliently held apart by the spring 34. Suitable friction-bearing disks 35-36 may be provided, one for each side of the units drive wheel 32, as particularly indicated in Fig. 3. Similar drive gear wheels 31-38 are provided, freely rotatable on the shaft 25 and frictionally coupled therewith by means of the flanged bushinglike members 39 lawhich are keyed to the drive shaft 25, one side of the drive wheel 31 being engaged by the flange extending from the bushinglike member 40 and one of the sides of the drive wheel 38 being similarlyengaged by the flange extending from the bushing member 39. Coacting Similarly flanged floating coupling or bushing mem- Known details and elements will be discussed only to the extent required for convey- A suitable cover Il may be provided,

bers 4I42 are disposed between the inner sides of the drive wheels 3'I38 and are held in frictional driving engagement therewith by the spring 43 which attempts to spread these floating bushing members apart, thus frictionally coupling the drive wheels 37-38 with the flanges of the bushings 39-40, respectively. The drive gear wheels 3'I-38 are associated with number wheels of higher numerical order, the drive wheel 31 being provided for the hundreds number wheel and the drive wheel 38 for the thousands number wheel.

A shaft 45 is disposed in the forward portion of the structure and is suitably held in slots such as 46 (see Figs. 1 and 4) provided in the side walls II and I3. Rotatably mounted on this shaft 45 are the number wheels 4'I50. The number wheel 47 is the units number wheel, and each of the remaining number wheels is a number wheel of progessively higher numerical order. Four number wheels have been shown for convenience of description; it is understood that more or less number wheels may be provided. Secured to each of the number wheels is a driven gear wheel which is normally in mesh with the corresponding drive gear wheel carried on the shaft 25. Thus, the units number wheel 41 carries the driven gear wheel 5|, and similar driven gear wheels 52.54 are associated with the number wheels 48-50, respectively.

Each driven gear wheel 5I-54 is provided with a pinlike control and stop member which extends axiall therefrom. These pinlike members are indicated in Fig. 2 by numerals 55-58, respectively, the pinlike member 55 associated with the driven gear wheel 5| being also shown in Figs. 4-7. The function of these members is to prevent rotation of the corresponding number wheels, in counter-clockwise direction, as shown in Figs. 4-3, beyond the normal position thereof, and to effect operative actuation of each number wheel of higher numerical order upon completion of a full revolution of the next adjacent number wheel of lower numerical order.

Each of these pinlike members 5558 is for this purpose normally in engagement with the free end of a control arm extending from a pivot-- ally mounted control bracket associated with the corresponding number wheel. Thus, as is particularly apparent from Figs. 2-5, the pinlike member 55 extending axiall from the driven gear wheel of the units number wheel 41 is normally in engagement with the free end of the control arm 60 extending from the control bracket 6I which is pivotally mounted on the shaft 62. A positioning arm 63 extends rearwardly from the control bracket for engagement normally with a stop rod or shaft 64 which, just like the shaft 82, is mounted between the side walls II and I3 of the structure. The control bracket 6| is also provided with an angular trip arm 65 for tripping a stop bracket I23 carrying a stop member I associated with the gear drive wheel 33 coacting with the tens number wheel 48 in a manner which will presently appear. An extension 66 projects from the control bracket 6| which coacts with a coiled spring 81, one end of which is secured to the extension 66 and the other end of which is anchored in the positioning shaft 64. The control bracket 6 I with its various arms, is thus normally held in clockwise direction, as seen in Figs. 4 and 5, with the free end of its control arm 60 in engagement with the pinlike projection 55 axially extending from the driven gear Wheel 5I associated with the units number wheel 41, and such number wheel is therefore prevented from rotating in counter-clockwise direction beyond its normal 0 position. However, when this number wheel is advanced in clockwise direction through a full revolution, the pin 55 will displace the arm 60 angularly in counter-clockwise direction to trip the stop arm I20 coacting with the drive wheel 33 o as to effect operative actuation of the tens number wheel. This transfer operation will presently be described more in detail.

A pivotally mounted control bracket such as 6| is associated with each of the remaining number wheels and their associated driven gear wheels. The corresponding control bracket coacting with the tens number wheel 48 and its driven gear wheel 52 is indicated by numeral I0. Just like the control bracket 6|, the pivotally mounted control bracket I0 ha an arm H, corresponding to arm 60 of bracket 8I, the free end of which is normally in engagement with the pinlike member 56 projecting from the driven gear wheel 52 of the tens number wheel 48, as particularly shown in Figs. 8 and 9. The control bracket 10 also has a positioning arm I2 (see Fig. 3) which engages the stop rod 64, a trip bracket I3 for interlocking coaction with the stop bracket I30 carrying the stop arm I2'I associated with the drive wheel 31 for coaction with the number wheel of next higher numerical order, and an arm I4 to which is secured one end of the spring I5, the other end of which is anchored in the stop rod 64. The control brackets 16-11 are similarly constructed and pivotally mounted on the shaft 62 for coaction with the number wheels 4950, respectively, the control member 18 having the control arm T8 which normally is in engagement edgewise with the pin 51 extending from the driven gear wheel 53 of the number wheel 49 (see also Fig. 3), and the control bracket 11 having an arm for engagement edgewise with the pin 58 projecting from the driven gear wheel 54 of the number wheel 50. The control bracket 16 also has an arm 8| which is in engagement normally with the stop rod 64, an angular trip bracket 82 which is in interlocking tripping relationship with the stop bracket coacting by means of its stop arm I22 with the drive wheel 38, which. meshes with the gear wheel 54 of the number wheel 50, and an extension 83 to which is attached one end of the spring 84, the other end of which is anchored in the. stop rod 84. The control bracket 11 is similarly constructed, having the control arm 80, already mentioned, and the arm 85 which is locked r in back of the stop rod 64 by the spring tension furnished by spring 86, one end of which is anchored in the extension 81 and the other end of which is anchored in the rod 64. There is no trip bracket such as 65, 13 or 82 associated with the control bracket I1 because it has been assumed that the counter has only four number wheels, and therefore the control bracket coacting with the number wheel of highest numerical order does not have a tripping function for transfer purposes.

The. trip or stop brackets I23, I30 and I32, carrying the stop arms I 20, I2 I, I22, respectively, are likewise pivotally mounted on the shaft 62, and are biased thereon in clockwise direction, as seen in Figs. 8 and 9, by springs secured to the extensions I24, I3I, I33, respectively, which are anchored in the stop rod 64.

It will be understood from the above discussion that, if the drive shaft 25 were rotated by the motor 20 in clockwise direction, as seen in 5 Fig. 4, such rotation would be frictionally efiective to the drive gear wheels 32, 33, 31, 38, attempting to rotate the driven gear wheels 5|, 52, 53 and 54 of the number wheels 4'|-50 in counter-clockwise direction. Such rotation is inhibited due to the engagement of the control pins 55-58 projectin from the corresponding driven gear wheels which are in engagement with the free ends of the associated control levers or arms 60, 'II, 38 and 30 projecting from the pivotally mounted control brackets GI, 10, I6 and 11, respectively. But, if it is assumed that the various number wheels, or some of them, have been advanced, clockwise as seen in Fig. 4, from their normal positions, the subsequent clockwise rotation of the shaft 25 would be efiective to rotate them counter-clockwise until the control pins 55-58 engage their coacting control levers 60, H, I8 and 80, respectively, when the number wheels are again in normal 0 position.

Each of the drive gear wheels 32, 33, 3'1 and 38 is provided with a number of axially extending projections for coaction with escapementlike drive control means yet to be described. Thus the drive gear wheel 32 carries the projections 90-43, as shown in Figs. 441, and the drive gear wheel 33 carries axial projections 94-31, as shown in Figs. 8 and 9. Similar projections are provided on each of the remaining drive gear wheels 3I.38, the corresponding projections provided on the drive gear wheel 38 being marked in Fig. 1 by numerals IUD-I03. The projections associated with each drive wheel constitute stop members for coaction with corresponding stop lever arms, one associated with each drive gear wheel to control the intermittent angular advance or rotation thereof.

The stop lever arm IIU associated with the drive gear wheel 32 coacting with the driven gear wheel SI of the units number wheel 41 is pivotally mounted at III. Pivotally mounted on the lever arm H0 is a latch member II2 having a camming arm H3 (see also Figs. 4-7). A spring H4 is provided, one end of which is anchored in the stop rod 64 and the other end of which is anchored in a bracket extension II5 of the latch member II2. This latch member with its camming arm I I3 is thus biased in counmr-clockwise' direction, as seen in Fig. 4, and biases in clockwise direction the stop lever arm IIO so that its free end is disposed in the path of the stop projection 90 carried by the drive gear wheel 32, preventing counter-clockwise rotation of this drive gear wheel when the shaft 25 is rotated counterclockwise by the motor 20.

The stop arms for coaction with the stop members axially projecting from each of the remaining drive wheels 33, 31 and 38 are marked by numerals I28I22, respectively. The stop arm I coacting with the drive gear wheel 33 extends from the pivotally mounted stop bracket I23, already mentioned, and has an extension I24 which interlocks with the angular trip member 65 of the pivotally mounted control bracket 6| which carries the control arm 30 coacting with the number wheel 41. The stop bracket I23 is biased in clockwise direction, by a spring anchored in the stop rod 64 which is secured to the extension I24, as seen in Figs. 3 and 9. The stop arm I2I coacting with the stop projections on the drive gear wheel 31 extends similarly from the pivotally mounted stop bracket I30 Which, is in interlocking tripping relationship with the angular trip member I3 extending from the control bracket I0 associated with the numberwheel 48; and the stop arm I22 coacting with the stop projections on the drive gear wheel 38 extends in a similar manner from the pivotally mounted stop bracket I32, its arm I33 being interlocked with the trip bracket 82 of the control bracket I6 which coacts with the number wheel 49.

The normal position of the various stop arms coacting with the drive gear wheels 33, 31, 38,

respectively, such as the stop arm I20 associated with the drive gear wheel 33, is indicated in Fig. 8. It will be seen from this figure that the.

free end of the stop arm I20 is in the path of the stop projection 96 carried by the drive gear wheel 33 to prevent the rotation of this drive gear wheel if the shaft 25 is rotated counterclockwise. The

remaining stop lever arms I2I-I22 are in simi-,

lar relationship with a stop projection on the drive wheels 3'I38, respectively, and it follows therefore that each of the drive gear wheels 33,

31 and 38 is held against rotation by the shaft wise rotation of the shaft 25.

Counter-clockwise rotation of the shaft 25 will thus have no effect so long as the mechanism and its various operating parts are in normal position, as discussed. Clockwise rotation of the shaft 25 will likewise be inefiective in normal position of the mechanism, due to the engagement of the control pins such as 55-58 with the free ends of the control lever arms such as 50 associated with the respective number wheels.

Secured to'the rodlike members I5I5, which interconnect the side walls I! and i3, is a platelike member I40 carrying a bracket I ll for mounting the electromagnet having the coil I42. Suitable ears are provided for pivotally mounted the armature I43 which is biased in counter-clockwise direction, as seen in Figs. 2, 3 and 4-9, by a spring I44 extending from a bracket I45. A suitable angular extension Mt (Figs. 2 and 3) may be providedfor limiting the counter-clockwise displacement of the armature I43 to normal position. Secured to the armature I43 is a latch member I41. This latch member is slotted at its free end, as particularly indicated in Figs. 2, 3 and 4, for accommodating the latch member I I2 which is pivotally mounted.

on the stop lever or arm Hi3; Accordingly, in normal position of the device the latch member is biased in downward direction, as seen in Fig. 4, and is unlatched from the coacting latch member I41 carried by the armature H13.

It will now be assumed that the motor 26 is operatively actuated to rotate the shaft 25 in counter-clockwise direction, as the structure is illustrated in Fig. 4, and that a series of impulses is delivered to the coil I42 of the electromagnet for the purpose of successively advancing the number wheels to display successively numerals of progressively higher order.

Upon delivery of the first impulse to the electromagnet, the armature I43 is attracted in clockwise direction, as seen in Fig. 4, and, inas- 'much as the pivotally mounted latch member H2 is biased in counter-clockwise direction by the spring I I l, this latch member II2 will interlock with the coacting latch member I41 and assume the relative position asseen in Fig. 5. The shaft 25, it will be recalled, rotates in counter clockwise' direction. The drive wheel 32' for driving the drivegea'r Wheel 5I of the units number Wheel 41 is still preventedfrom rotating, by frictional force transmitted to: it through the couplings including the busliinglike members 28 and 33 because the free edge or the stop lever arm III] is in the path of rotation of the projection 9% axially extending from the drive wheel 32. It may be'mentioned here that the displacement of the stop arm Ht is limited by a stop bracket I50 extending from the plate Mil, hold ing the arm I IG in the position shown.

Upon cessation of the first impulse, the armature I43 released to normal; and, inasmuch as latchmember H2 is now interlocked with the c'oacting latch member IQI, therelease of armature to normal carries the latch member H2 and therewith the stop lever arm I I counterclockwise tothe position in which the parts are shown in Fig. 6, the displacement being against the pull of the spring H4. The free end of the stop lever arm IE is thus removed from engagement with the stop projection 53' carried by the drive gear wheel 32, and this wheel can rotate counter-clockwise, being frictionally coupled with the rotating shaft 25.

The relative position of the parts at the inception of rotation of the drive wheel 32 is apparent from Fig. 6. The driven gear wheel 5i of the units wheel 4'! has been angularly displaced, as shown in this figure, and the control pin 55 axially projecting from the driven gear wheel 5i moves away from the control lever arm 60. The stop projection 93 now engages the camming arm II3 associated with the latch II2 and moves the camming arm to the lei t, thereby rotating the latch member II2 clockwise, thus releasing its interlocking engagement with the coacting latch member I41 and allowing the stop lever arm IE!) to drop into its normal position, as indicated in Fig. 'I, in which position it is in the path of the stop projection 9| to intercept this projection and stop rotation of the drive gear wheel 32 when the stop projection 9| reaches the relative position in which the stop projection 90 is shown in Figs. 4 and 5.

The drive gear wheel 32 now has been advanced by a certain angular amount and, being geared with the driven gear wheel SI of the units number wheel 4'1, it has rotated this gear, and therewith the units wheel, by 36, appropriate ratio of the gears being provided, and the units number wheel is thus advanced to display through its sight opening the number 1.

Successive impulses delivered to the coil I42 of the electromagnet cause successive attraction and subsequent release of the armature I43 and thereby successive latching and unlatching of the coacting latch members H2 and MT, and in termittent lifting and releasing of the stop lever arm III], as described, thus successively efiecting the operative coupling of the drive gear wheel 32 for rotation with the shaft 25 and successively arresting its rotation after it has been displaced angularly by the amount determined by the angular spacing of the stop members 9093, respectively. The units number wheel 41 is thus angularly advanced step by step to display successively its numerals of progressive- 1y higher numerical order, until the tenth impulse is delivered, at which time the units number wheel again displays 0. Upon delivery or, rather to say, upon cessation of the tenth impulse, both, the units and the tens number wheels 41 and 48 must be rotated to display their numeral 1.

The operation of the units number wheel has been explained; the advance of the tens number wheel 48 is accomplished by the interlocking coaction of the control bracket 6i, associated with the units number wheel, with the stop bracket I23 carrying the stop lever arm I20. It is as sumed in Fig. 8 that the driven gear wheel 5| of the units wheel 4'? has been advanced, as described, in clockwise direction, the control pin 55' being shown approximately 180 removed from the position in which it has been shown in Figs. 4 and 5. The corresponding control pin 56 asso ciated with the driven gear wheel 52 of the tens' number wheel 48 is in engagement with the free edge of the control arm II and the stop arm I20 extending from the pivotally mounted stop bracket I23 is inengagement with the stop projection 98 extending from the drive gear wheel thus preventing this drive wheel from rotating with the shaft 25. The units wheel finally goes into its 0 position, thereby moving its control pin 55 with respect to the control arm 60, displacing this control arm in counter-clock wise direction, as indicated in Fig. 9, thus likewise disp-lacing its angular trip member 65 relative to the interlocking extension I24 of the stop bracket i23 (see also Fig. 3) and moving this bracket, and therewith the stop arm I 20, into the position shown in Fig. 9. The free end of the stop arm I23 is thus removed from the path ofrotation of thestop projection 96' extending from the drive gear wheel 33, and this drive wheel, -coincident with the rotation of the units number wheel to display the numeral 0, responsive to cessation of the tenth current impulse delivered to the coil hi2 of the electromagnet, will therefore be able to rotate with the shaft 25 in counterclockwise direction, thereby rotating the driven gear wheel 52 and therewith the tenths number wheel 48 by 36, or one step, at which time the control pin 55 of the driven gear wheel 5! of the units number wheel has passed its normal posi-' tion, allowing the control arm 66 to return to normal, as seen in Figs; 4 and 5, thus returning the stop bracket I23, and therewith the stop lever arm I25, to normal, disposing it in the path of the stop member 97. The" counter now registers numeral 10. The following series of ten impulses will again be effective to rotate the units number wheel step by step, as already described. Upon cessation of the twentieth impulse, the transfer will again be effected to step the tens number wheel 48 to displa the numeral 2 in the same manner as this number wheel was advanced by one step upon delivery of the tenth impulse to the electromagnet. The counter now registers the numeral 20.

The operation continues in this manner, the tens number wheel being advanced one step for every ten steps of the units number wheel, and when the tens number wheel has completed a revolution, its control pin 56 will displace the control arm I I extending from the control bracket 'IO (Fig. 3) to trip the stop bracket I30 so as to remove the stop arm I2I from the path of the corresponding stop projection on the drive wheel 31 to allow'this drive Wheel to move the third number wheel 49 by one step, and so on, until the third number wheel has completed a revolution, when it will effect tripping of the stop bracket I32 to effect rotation of the drive gear wheel 38 for rotating the final number wheel 5|] by one' step. Each number wheel effects in this manner,

coincident with completion of one full revolution,

the operative actuation of the adjacent number wheel of higher numerical order.

When it is desired to restore the counter to 0 position from any numerical position to which it may have been advanced, the motor 20 is caused to rotate the shaft 25 in reverse direction, clockwise as seen in Figs. 4-9. The number wheels having been advanced to some numerical position, their associated control pins 5558 are out of engagement with their respective control lever arms such as 60, ll, 18 and 80. There is nothing .to oppose the clockwise rotation of the drive gear wheels 32, 33, 31 and 38 attempting to rotate in counter-clockwise direction the associated driven gear wheels of the various number wheels, and these gear wheels are therefore simultaneously rotated in counter-clockwise direction untilitheir associated control pins 55-58 encounter the coacting control arms such as 60, H, 18 and 80, when the return rotation will be stopped. The number wheels are then again in zero position.

The resetting of the counter to 0 from any numerical position to which it has been advanced is thus accomplished practically instantaneously because, even if it is assumed that each of the number wheels has been advanced to its highest numerical position, which is numeral 9, it will require less than one full revolution of the shaft 25 to return the number Wheels to 0.

Numeral I indicates a suitable terminal device for connecting the electromagnet with a desired source of impulses and for properly wiring the reversible motor and such auxiliary means as switches and the like to obtain the operations explained in the foregoing description.

A relatively large-scale embodiment has been shown, but it is understood that the structure may be made as large or as small as practicable and desirable.

Changes may be made within the scope and spirit of the appended claims.

I claim:

1. A numerical counter comprising a number wheel, a drive wheel for said number wheel, motor means for applying constant torque to said drive wheel which normally attempts to rotate said number wheel in forward add direction, stop means for normally inhibiting the rotation of said drive wheel, said stop means comprising a stop member on said drive wheel which projects axially therefrom, a pivotally mounted stop lever for engagement with said stop member, a latch member pivotally mounted on said stop lever, impulse-controlled electromagnetic means, and a latch member controlled by said electromagnetic means for coaction with the latch member on said stop lever, whereby said stop lever is intermittently released responsive to successive operative actuation of said electromagnetic means to allow said torque to become intermittently operatively effective to rotate said drive wheel for rotating said number wheel.

2. The structure and combination defined inv claim 1, wherein said motor means is adapted to rotate said drive wheel and therewith said num- --ber wheel in reverse direction torestore the number wheel to 0 position from any numerical position to which it may have been advanced, a --pivotally mounted stop arm disposed, alongside -said number wheel, and a pinlike stop member carried by said number wheel and axially projecting therefrom for engagement with the free end of said stop arm responsive to reverse rotaand therewith said lever arm relative to said stop member to permit rotation of said drive tion of said number wheel for stopping further reverse rotation thereof when said number wheel reaches 0 position. i Z 1, 5

-3.- A numerical counter comprising a units number wheel and a plurality of additional'number wheels of progressively higher numerical order, a driven gear wheel associated with each number wheel, a drive gear wheel for and meshing with'each driven gear wheel, motor means for applying constant torque to all drive gear wheels for the purpose of attempting to rotate said gear wheels so as to rotate said number wheels in forward add direction, stop means associated with each drive gear wheel for normally inhibiting the rotation thereof,-latch means individual to the stop means associated with the drive gear wheel for the units number wheel, impulse-responsive electromagnetic meansfor intermittently releasing said latch means to allow said torque to become intermittently operatively effective to rotate the units number wheel successively by predetermined angular amounts, and trip means'operable by each number wheel at the conclusion of a full revolution thereof for momentarily releasing the stop means associated with the drive gear wheel for the number wheel of next higher numerical order to allow said torque to-become operatively effective to rotate such number wheel by a predetermined .angular amount.

4. A-numerical counter comprising a rotatable units number wheel, a rotatable drive shaft, .motor means for continuously rotating said drive shaft, a drive wheel rotatably disposed on said drive shaft and geared with said units number pivotally mounted lever arm, a stop member projecting axially from said drive wheel, a latch member pivotally mounted on said lever arm,

.means for resiliently biasing said latch member and therewith said lever arm to dispose the free end of such lever arm normally in the path of said stop member to inhibit the rotation of said drive wheel, an impulse-responsive electromagnet,

a coacting latch member operatively effective responsive to the energ zation of said electromagnet for lifting said pivotally mounted latch member wheel, whereby said lever arm is intermittently operatively actuated responsive to successive energization of said electromagnet to allow successive rotation of said drive wheel for successivel advancing said units number wheel by predetermined angular amounts.

5.- A numerical counter comprising a rotatable units nur ber wheel, a rotatable drive s aft, motor means for continuously rotating saiddrivev shaft, a dr ve wheel rotatably d s o ed on said drive shaft and geared with said units number wheel, coupling means for frictionallv coupling said drive wheel with said drive shaft attempting to rotate such drive wheel and therewith said units number wheel in forward add direction, a pivotally mounted lever arm, a stop member projecting axially from said drive wheel, a latch member pivotally mounted on said lever arm,

means for resiliently biasing said latch member and therewith said lever arm to dispose the free end of such lever arm normally in the path of said stop member to inhibit rotation of said drive wheel, an impulse responsive electromagnet, a

for limiting the amount of angular advance of said drive wheel.

6. In a numerical counter, a plurality of num 'ber wheels of progressively higher numerical order disposed rotatably side by side on a common shaft, a driven gear wheel associated with each number wheel, a drive shaft and motor means for continuously rotating it, a drive gear wheel for each driven gear wheel, a friction clutch member for each drive gear wheel carried on said drive shaft, a coacting friction clutch member for each drive gear wheel, means for axially resiliently biasing each coacting clutch member to engage its associated drive gear wheel for transmitting frictional driving power thereto, a

pivotally mounted lever arm associated with each drive gear wheel for normally inhibiting the rotation thereof, an impulse responsive electromagnet, an escapement device controlled by said electromagnet for intermittently releasing the lever arm associated with the drive gear wheel coacting with the driven gear wheel for the number wheel of lowest, numerical order to allow rotation of said drive gear wheel for advancing the corresponding number wheel of lowest numerical order successively by predetermined angular amounts, said escapement device comprising a plurality of angularly spaced stop members axially projecting from the drive gear wheel coacting with the number wheel of lowest numerical order, a latch member pivotally mounted on the associated lever arm. means for resiliently biasing said latch member and said lever arm to hold the free end of such lever arm normally in engagement with one of said stop members to inhibit rotation of said drive gear wheel, a coacting latch member actuated by said electromagnet upon energization thereof for interlocking with said pivotally mounted latch member to lift such latch member and associated lever arm upon deenergization of said electromagnet for the purpose of releasing the engagement thereof with said stop member to allow rotation of the corresponding drive gear wheel, .a camming member associated with said pivotally mounted latch member for engagement by the stop member to release the pivotally mounted stop member from the coacting latch member to restore said lever arm to normal position in which its free end is contacted by one of Said stop members to determine the amount of angular displacement of said drive gear wheel incident to each operative actuation of said electromagnet, and trip means actuated by each number wheel incident to completion of a full revolution thereof for momentarily releasing the lever arm associated with the drive gear wheel enacting with the number wheel of next higher numerical order to allow rotation of such drive wheel for rotating the corresponding number wheel by a predetermined angular amount.

' 7. A numerical counter comprisin a plurality of number wheels of progressively higher numerical order arranged for individual rotation side by side on a common relatively tationary none rotatable shaft, adrive shaft, areversible motor for selectively continuously driving said drive shaft in either one or the other direction of rotation, a drive wheel for each number wheel rotatably disposed on said drive shaft and frictionally resiliently coupled therewith, a plurality of angularly spaced stop members axially projecting from each drive wheel, a pivotally mounted stop lever arm for stop engagement with one of the stop members of each drive wheel to inhibit rotation thereof in one direction of rotation of said drive shaft, namely, in the direction effective to rotate the associated number wheel in forward add direction, a control member associated with each number wheel, a pivotally mounted control lever arm for each number wheel arranged for engagement by the corresponding control member there of in normal 0 position of such number wheel to inhibit rotation of such number wheel in reverse direction from said 0 position thereof incident to corresponding rotation of said drive shalt, an impulse-responsive electromagnet, an escapement device associated with the drive wheel for driving the number wheel of lowest numerical order controlled by said electromagnet for intermittently releasing the associated stop lever arm to allow the corresponding drive wheel to rotate for the purpose of rotating the coacting number wheel successively by predetermined angular amounts, and interlocking means actuated by the control lever arm associated with each number wheel incident to completing a full revolution thereof for momentarily releasing the stop lever arm of the drive wheel associated with the number wheel of next higher numerical order to cause rotation of such drive wheel by a predetermined angular amount.

8, In agnumerical counter, a stationary shaft, a units number wheel and a plurality of number wheels of higher numerical order rotatably mounted on said stationary shaft, a driven gear wheel for each number wheel, a rotatable drive shaft, a drive gear wheel for and in mesh with each driven gear wheel, said drive gear wheels being rotatable on said rotatable drive shaft, friction means for coupling said drive gear wheels with said drive shaft to rotate such drive gear wheels and therewith the coacting driven gear wheels and the corresponding number wheels associated therewith, stop means carried by each drive gear wheel, detent means for coaction with the stop means of each drive gear wheel to inhibit rotation thereof in a direction corresponding to forward rotation of its associated number wheel, stop means carried by each number wheel, detent means for coaction with the stop means carried by each number wheel to inhibit rotation thereof in the reverse direction beyond a predetermined position which corresponds to the "0 position thereof, electromagnetic impulse responsive means for intermittently actuating the detent means coacting with the stop means of the drive wheel for the units number wheel to allow rotation of such drive wheel for rotating the units number wheel to display its successively higher numerals, and trip means operated by the detent means of each number wheel, except the number wheel of highest numerical order, upon completing a full revolution, for momentarily actuating the detent means coacting with the stop means carried by the drive gear wheel of next higher numerical order to allow such drive gear wheel to rotate its corresponding number wheel to record a count.

9. In a numerical counter of the class described, a stationary shaft, a units number wheel and a plurality of number wheels of higher numerical order rotatably disposed on said stationary shaft, a rotatable shaft, drive means for each number wheel carried on said rotatable shaft, detent means for each drive means to prevent rotation thereof in a direction corresponding to forward add rotation of its associated number wheel, electromagnetic impulse responsive means for intermittently actuating the detent means coacting with the drive means of the units number wheel to allow forward rotation of said units number wheel by angular amounts so as to display its successively higher numerals, a stop member carried by each number wheel, and a pivotally mounted control lever arm for coaction with each stop member, said lever arm having the dual function of causing under control of said stop member upon completion of a full forward revolution of its associated number wheel momentary release of the detent means for the drive means of the number wheel of higher numerical order to allow such drive means to rotate its number wheel forwardly by a predetermined amount and of preventing rotation of its associated number wheel in reverse direction beyond a predetermined angular position by engagement of said stop member with its free end.

MARTIN L. NELSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 926,151 Vincent June 29, 1909 1,447,871 Lake Mar. 6, 1923 1,830,756 Ford Nov. 10, 1931 20 2,077,902 Saxby Apr. 20, 1937 

